Certain prior door stops for overhead doors have been of wood and have been disadvantageous because the wood stop must be mounted a sufficient distance from the door to allow for swelling of the wood due to weather conditions causing binding of the door. Such clearance results in a gap allowing air infiltration to occur. Further, such door stops require painting at frequent intervals to maintain the proper clearance from the door and to inhibit wood decay. Also, nails typically used to fasten such door stops are subject to corrosion causing unsightly rust streaks.
Certain other prior constructions include door stops of molded or extruded plastic material which require clearance from the door and thus do not provide a sealing contact with the door surface. Attempts to remedy this deficiency have included extending a flexible sealing strip from the door stop, but in use repeated openings and closings of the door have distorted the sealing strip and destroyed its effectiveness. Also, these door stops of formed plastic material require exposed fasteners subject to corrosion.
A solid contact between the stop surface and the door is necessary because of a clearance requirement between the rollers on the door and the track guiding the rollers. It is very desirable that the door stop be positioned so that as the door approaches fully closed position, a wedging action takes place with the door stop as provided for by the clearance between the rollers and track. Otherwise, the only contact between the door and stop is with the flexible strip which is subject to distortion in use.
Other prior constructions include stops having substantially flat metal strips mounting discrete flexible strips of vinyl material or the like extending therefrom to make sealing contact with the door surface. Difficulty is had with this stop due to the lack of surface contact between the stop per se and the door which is required to take up the clearance between rollers and track as discussed above, and which results in relying solely on contact with the distortable flexible material when the door is closed. Also, such constructions require exposed fasteners which are subject to corrosion.
A further disadvantage of these formed plastic and metal door strips is that because of the substantial differences in coefficient of expansion between the door stop and the door jamb to which it is fastened, the stop expands and contracts between the spaced fastening points, resulting in gaps in the sealing surface of the stop as well as an unsightly appearance.